全文获取类型
收费全文 | 8465篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 5篇 |
化学工业 | 35篇 |
金属工艺 | 7篇 |
建筑科学 | 3篇 |
能源动力 | 1篇 |
轻工业 | 12篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 13篇 |
冶金工业 | 8359篇 |
原子能技术 | 1篇 |
自动化技术 | 14篇 |
出版年
2020年 | 3篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 277篇 |
1998年 | 2676篇 |
1997年 | 1481篇 |
1996年 | 948篇 |
1995年 | 547篇 |
1994年 | 420篇 |
1993年 | 526篇 |
1992年 | 61篇 |
1991年 | 103篇 |
1990年 | 99篇 |
1989年 | 88篇 |
1988年 | 93篇 |
1987年 | 91篇 |
1986年 | 95篇 |
1985年 | 65篇 |
1984年 | 1篇 |
1983年 | 9篇 |
1982年 | 35篇 |
1981年 | 37篇 |
1980年 | 77篇 |
1979年 | 2篇 |
1978年 | 12篇 |
1977年 | 181篇 |
1976年 | 431篇 |
1975年 | 9篇 |
1963年 | 2篇 |
1955年 | 7篇 |
1954年 | 1篇 |
排序方式: 共有8468条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
P Melgarejo Moreno D Hellín Meseguer JA Ruiz Macía I Ribera-Cortada 《Canadian Metallurgical Quarterly》1997,24(5):451-456
Changes in the membrane potential of Saccharomyces cerevisiae were monitored by the electrochromic probe 3-(4-(2-(6-(dibutylamino)-2-naphthyl)-trans- ethenyl)pyridinium)propanesulfonate (di-4-ANEPPS) that should incorporate into the plasma membrane. The probe had suitable spectral characteristics and exhibited an electrochromic shift upon a change in membrane potential but the magnitude of the response increased with time. The presence and properties of the cell wall affected the extent of cell staining. The time dependence of the fluorescent response indicated that the probe was not incorporated solely into the plasma membrane but spread gradually into the whole cell; this was confirmed by confocal microscopy. The probe is therefore suitable for assessing membrane potential changes only over time intervals up to 30 min. Longer monitoring will require either a modified staining protocol or a derivatization of the probe molecule. As found by using the dioctyl derivative di-8-ANEPPS, extending the aliphatic chains of the di-4-ANEPPS molecule does not prevent the dye from penetrating into the cell or liposome interior and, in addition, impairs staining. 相似文献
65.
66.
We reviewed the use of a low radiation portable fluoroscopy unit in 100 patients. The most common indication was closed reduction of distal radial fractures. Fracture and joint stability were assessed on the real-time monitor and stored on videotape. Static images were stored on thermographic paper. Fluoroscopically guided joint injections and localization of implants, foreign bodies and bone tumours were performed. Fluoroscopy is a useful adjunct to arthroscopic assisted fracture reduction and other arthroscopic procedures such as distal ulnar resection. These new generation units produce superior resolution images, are easy to manoeuvre and do not require a radiographer. 相似文献
67.
68.
69.
I Scott J O'Shea M Bunce JM Tiercy JR Argüello H Firman J Goldman HG Prentice AM Little JA Madrigal 《Canadian Metallurgical Quarterly》1998,92(12):4864-4871
In comparison with HLA-matched sibling bone marrow transplants, unrelated donor transplants are associated with increased graft-versus-host disease and graft failure. This is likely in part due to HLA incompatibilities not identified by current matching strategies. High resolution DNA-based typing methods for HLA class II loci have improved donor selection and treatment outcome in unrelated donor bone marrow transplantation. By using DNA-based typing methods for HLA-A and -B on a cohort of 100 potential bone marrow donor/patient pairs, we find that serological typing for HLA class I is limited in its ability to identify incompatibilities in unrelated pairs. Furthermore, the incompatibilities identified are associated with the presence at high frequency of alloreactive cytotoxic T-lymphocyte precursors. DNA typing also indicates that HLA-C mismatches are common in HLA-A and -B serologically matched pairs. Such mismatches appear to be significantly less immunogenic with respect to cytotoxic T-lymphocyte recognition, but are expected to influence natural killer cell activity. Thus, improved resolution of HLA class I shows many previously undisclosed mismatches that appear to be immunologically functional. Use of high resolution typing methods in routine matching is expected to improve unrelated donor selection and transplant outcome. 相似文献
70.